In underground mining in general, and in underground coal mining specifically, dust suppression and methane dilution are required for the safety and health of mine personnel. Both state and federal regulatory agencies have required, and will continue to stringently require the observance of regulations designed to insure the safety and health of such personnel. Accordingly, any change in machinery or method of operation related to dust suppression or methane dilution will be subjected to even more exacting tests.
The problems associated with methane and dust in coal mines have, in some cases, necessitated that otherwise profitable and productive working sections of mines be, at least temporarily, closed. Solutions to these problems have been attempted before with limited success. Although large volumes of air are circulated throughout coal mines, there still exists the possibility that, at the working faces while machines are mining the coal, that pockets or corners exist which have relatively still air. If the coal mine is troubled with methane liberation through the coal seam, these pockets or corners can hold sufficient quantities of methane and coal dust to provide an ignitable mixture. An obvious answer to this problem is to blow air into these pockets and dilute the concentration of methane and coal dust to safe levels.
While the solution is easily stated, it is not easily implemented. The primary problem is in finding a suitable blower or blowers that can be mounted at the front end of a coal mining machine and which can be operated safety and efficiently in a cramped and spacially depleted environment.
Water-powered venturis have been used in the past for the suppression of dust. These designs, while sufficient for their specifically contemplated operation, do not operate as air pumps for methane dilution. It should be obvious that in cramped quarters, a redundancy of machinery is not desirable.